Key Guidelines and Evidence: Ventricular Arrhythmias

Monomorphic VT

Guideline Recommendations for Medications in Monomorphic VT

Summary of Key Trials

• PROCAMIO Trial (2017): Procainamide superior to amiodarone for conversion of stable MVT (67% vs 38%, p<0.05) with fewer adverse events
• Marill et al (2010): Retrospective analysis found amiodarone and procainamide had similar efficacy for stable MVT (59% vs 43%, p=0.08)
• AHA/ACC/HRS guideline update (2017) changed recommendation to procainamide preferred over amiodarone based on efficacy and safety data

Polymorphic VT

AHA/ACC/HRS (2017)

• Intravenous magnesium can suppress episodes of torsades de pointes without necessarily shortening QT, even when serum magnesium is normal. Repeated doses may be needed, titrated to suppress ectopy and nonsustained VT episodes while precipitating factors are corrected.
• In patient with recurrent torases de pointes associated with acquired QT proklongation and bradycardia that cannot be suppressed with intravenous magnesium administration, increasing the heart rate with atrial or ventricular pacing or isoproterenol are recommended to suppress the arrhythmia
• Maintaining serum potassium between 4.5 mEq/L and 5 mEq/L shortens QT and may reduce the chance of recurrent torsades de pointes

Key Study

• Tzivoni D, Banai S, Schuger C, Benhorin J, Keren A, Gottlieb S, Stern S. Treatment of torsade de pointes with magnesium sulfate. Circulation. 1988 Feb;77(2):392-7.
  • Twelve consecutive patients who developed torsade de pointes (polymorphous ventricular tachycardia with marked QT prolongation, TdP) over a 4 year period were treated with intravenous injections of magnesium sulfate.
  • In nine of the patients a single bolus of 2 g completely abolished the TdP within 1 to 5 min, and in three others complete abolition of the TdP was achieved after a second bolus was given 5 to 15 min later.